Association between anticholinergic drug prescription changes and rehabilitation outcome in post-acute hip fractured patients

Abstract

Purpose: To follow changes in anticholinergic drug prescriptions throughout hip fractured patients’ rehabilitation; to assess whether a change in anticholinergic burden affects rehabilitation outcome.Methods: Retrospective study of 869 hip fractured patients admitted between January 2011 to October 2015, performed in a post-acute geriatric rehabilitation center. The Anticholinergic Cognitive Burden Scale quantified the anticholinergic burden. Main outcome measures: Functional Independence Measure, motor Functional Independence Measure, Montebello Rehabilitation Factor Score on motor Functional Independence Measure and length of stay. Multiple linear regression analysis tested for independent association between admission anticholinergic burden and anticholinergic burden change during rehabilitation, and rehabilitation outcomes.Results: One hundred and sixty two (18.7%) patients were prescribed additional anticholinergic medications upon discharge; 76 (8.7%) were prescribed fewer. Patients with high admission anticholinergic burden presented with a significantly higher rate of higher education, less likely to reside at home, less independent pre-fracture, exhibited a significantly lower admission and discharge Functional Independence Measure score, a lower Functional Independence Measure score change and a lower Montebello Rehabilitation Factor Score. Admission anticholinergic burden, but not changes in anticholinergic burden during rehabilitation, was found to be independently associated with rehabilitation outcome (discharge FIM score).Conclusions: High admission anticholinergic burden is associated with lower functional ability in hip fractured patients. Changes in anticholinergic drug prescription during rehabilitation were not associated with rehabilitation outcomes.Implications for rehabilitationClinicians should make an effort to reduce AC drug use in hip fractured patients on admission to post-acute rehabilitation.AC burden should be carefully monitored throughout the rehabilitation period and reduced whenever possible.When functional ability does not improve as expected, AC burden should be considered as an intervening factor.